Hurricane Earl

Pre-Landfall 3 | Summary
Posting Date: September 1, 2010, 8:53:00 AM

AIR Worldwide estimates that insured losses from Hurricane Earl’s passage near the northern Leeward Islands earlier this week are between 50 million USD and 150 million USD. The estimate includes wind damage to insured onshore properties in the Virgin Islands, St. Maarten, St. Martin and Puerto Rico. Nearly half of the total is attributed to St. Maarten where high winds downed trees and power lines, and peeled off roofs and signage.

Hurricane Earl, having pulled away from the Leeward Islands yesterday while still at Category 4 strength, is now a Category 3 storm as it makes its closest approach to the North Carolina coast. It could arrive there as early as Thursday evening, bringing strong winds and tall waves. Some fluctuations in Earl’s intensity are possible as it tracks northward, but it is likely to remain at Category 3 strength for at least 48 hours. As of the NHC’s 11 am advisory today, Earl is about 170 miles east northeast of San Salvador in the central Bahamas and about 725 miles south southeast of Cape Hatteras, North Carolina. The storm is moving northwest at 17 mph, up from 14 mph yesterday, with maximum sustained winds of 125 miles per hour. Its hurricane-force winds extend 90 miles outward from the center. A hurricane warning is in effect from Bogue Inlet, North Carolina, northeastward to the North Carolina/Virginia border; this includes the Pamlico and Albemarle Sounds. A hurricane watch is in effect from the North Carolina/Virginia border northward to Cape Helopen, Delaware. A tropical storm warning is in effect from Cape Fear west of Bogue Inlet. Large swells from Earl have already begun affecting the United States’ southeastern coast, and are likely to result in dangerous surf conditions and rip currents. Officials in North Carolina have ordered a mandatory evacuation of Ocracoke and Hatteras Island. Additional evacuations may follow, if necessary. Earl, which only became a hurricane on Sunday, strengthened rapidly since its formation. It is expected to continue its movement toward the northwest today, with a gradual turn to the north-northeast on Friday, pushed out by a mid-latitude system moving out of the Great Lakes. On its current path, Earl should miss the Bahamas, passing well east and northeast of these popular tourist islands. Large swells may impact the southeastern Bahamas today, however, and a tropical storm warning is presently in effect for the Bahamas island of San Salvador. Tropical storm force winds could have an impact there later this morning. Isolated pockets of the southeastern Bahamas and the Turks and Caicos Islands could receive up to 4 inches of rain.

Earl Heads Toward North Carolina

Earl is expected to make its closest approach to North Carolina on Friday morning, at Category 3 strength. According to the National Hurricane Center’s most likely track as of the 11 am advisory, the center of Earl will bypass the tip of Cape Hatteras about 75 miles to the east. Even without making direct landfall, coastal areas of the Outer Banks are likely to feel Earl’s impact, including tropical storm force winds and high waves. If Earl tracks further west, storm surge could pose a real threat. Results of AIR’s analysis show that for the left-most NHC track, the greatest surge risk will be along the Outer Banks of North Carolina. The risk diminishes substantially if Earl tracks along the central portion of the NHC cone of uncertainty.

Figure 1: AIR's modeled storm surge risk (using a modified version of NOAA’s SLOSH model) associated with the left-most path in the NHC's forecast’s cone of uncertainty at 8:00 AM EDT (Source: NHC).

The last major hurricane to make landfall in North Carolina was Hurricane Floyd in 1999. Floyd caused estimated insured losses of USD 2 billion in 1999 dollars and was the state's deadliest hurricane.

Forecast Track toward the Northeast and Canada

Earl is currently being impacted by an environment of dryer air from the north and increased shear from a trough of low pressure from the southwest. These conditions will persist for the next day and should limit any further intensification of Earl. However, while some additional decrease in wind speed is possible, Earl should maintain its current intensity as it approaches North Carolina and still be a major hurricane with near 120 mph winds as it passes by that area. Despite the fact that Earl will start to decay as it turns toward the northeast and moves beyond the Outer Banks, it is still expected to pack winds of up to 100 mph as it moves off the coast of Cape Cod—and it may still be at hurricane intensity when it finally comes onshore in Nova Scotia. According to the NHC’s current most likely track, Earl will pass about 70 miles to the east of Cape Cod and 60 miles from Nantucket. It is important to note that while the forecast models continue to be in good agreement on the track forecast, there is still considerable uncertainty inherent is these predictions. Small deviations in track as the storm approaches North Carolina during the next day could lead to significant changes in the outlook.

Impacts in the Caribbean

Earlier this week, Earl’s heavy rain and wind caused damage in some of the northern Leeward Islands, blowing roofs off homes, flooding low-lying areas, and disrupting electricity. Earl’s largest impact in many of the northern Leeward Islands was flooding; Antigua received 7 inches of rain and 10-foot waves came ashore on its coast. The majority of the northernmost Leeward Islands reported some localized flooding. In Anguilla, winds of 80 to 90 mph blew the roofs off buildings and caused damage to many utility poles. Homes were also damaged in Antigua, St. Maarten, and Barbuda. The closest island to Earl’s center was Anegada, in the British Virgin Islands; its marina sustained significant damage. On Anegada and the island of Tortola, many boats and ferries were damaged or sunk. The storm diverted cruise ships across the region and canceled flights. Vacationers were stranded in Anguilla, the British Virgin Islands, the U.S Virgin Islands and Puerto Rico after airports closed. It should be noted that AIR’s insured loss estimates for this region are for modeled countries only; these are Puerto Rico, St. Maarten, St. Martin and the U.S. Virgin Islands. AIR estimates that 40 to 50% of losses are from St. Maarten.

Tropical Storm Fiona

Meanwhile, Tropical Storm Fiona, which formed Monday evening, is currently located approximately 70 miles northeast of Barbuda. With maximum sustained winds of 60 mph, up from 40 mph yesterday, it is currently moving west-northwest at 15 mph. A tropical storm warning is in effect for St. Martin and St. Barthelemy and a tropical storm watch is in effect for many of the northern Leeward Islands. On its current track, Fiona should pass near or just north of these islands today and tropical storm conditions could impact them this morning and afternoon. Portions of these islands may receive up to five inches of rain. While some strengthening is possible, Fiona is not expected to develop into a hurricane in the next five days. The AIR tropical cyclone team will closely monitor the progress of Earl and other developments in the Atlantic and will continue to provide updates as warranted by events. The information contained in this and past NewsALERTs is available on the ALERT website. Note that AIR’s insured loss estimates for the Caribbean reflect: • Insured wind damage to onshore property (residential, commercial/ industrial, auto), both structures and their contents They do not reflect: • Business interruption losses • Losses to uninsured properties • Losses to infrastructure • Losses from non-modeled secondary perils, including coastal and inland flood • Other non-modeled sources of loss, including loss adjustment expenses, clean-up of debris and hazardous waste materials

Pre-Landfall 3 | Downloads
Posting Date: September 1, 2010, 8:53:00 AM